The goal of this project is to develop and pilot an obesity intervention for use with teen mothers to prevent obesity in their preschool children using formative and feasibility research with a small RCT pilot study. There is currently a paucity of research on obesity prevention (ObP) interventions focused on preschool-aged children, low socioeconomic status (SES) and ethnic minority populations; and no interventions designed specifically for ObP for children of teen mothers. Teen mothers are a unique at-risk population with whom to intervene for ObP among their offspring. Parenting skills (e.g. parental modeling) are individual and intrapersonal mechanisms for ObP among children and their parents. Teen mothers are often from ethnic minority and low socioeconomic backgrounds and at high risk for poor parenting skills and obesity. The proposed intervention will be an innovative adaptation of empirically supported ObP and parenting interventions not previously used with this population. The specific aims of this project are to (1) conduct formative research using semi-structured interviews with (n=30) teen mothers and convene an expert panel to construct a developmentally and culturally appropriate intervention for teen mothers (ages 16-20 years) to prevent obesity with their children (ages 2-5 years). Formative research will guide selection of target behaviors and performance objectives, personal and environmental factors, change objectives, and intervention and evaluation methods; (2) To conduct a pilot study to evaluate the feasibility, developmental, & cultural appropriateness and acceptability of the intervention vs. a print-based wellness control group with teen parent- preschooler dyads (n=46) to inform a future RCT. This will include (a) Feasibility & acceptability testing based on process evaluation of recruitment, retention and intervention methods and measures. We will examine participant accrual and retention rates, acceptance of randomization, and compliance with study protocols. We will use quantitative measures to gauge participant satisfaction with all aspects of the intervention and protocol; (b) Exploratory effect size estimates of the impact of treatment on changes in and maintenance of child behavior, ObP and BMI. We will assess treatment effects by dose as part of exploratory analyses; (c) We will recruit teen mothers from the intervention group (n=8) to participate in a post-pilot feedback focus group to identify additional facilitators and barriers to ObP with their children including study protocol compliance and satisfaction, and likes & dislikes about the intervention. These data will be used to refine protocols (e.g., manual development & eligibility criteria) for future studies. Children of teen mothers demonstrate significant PA and nutritional risks for obesity; also, low SES, ethnic minority background, and developmental vulnerability are associated with teen parenting and significant risk factors for obesity. This project will be the first to develop and pilot an Obesity Prevention treatment for preschool children of teen mothers.